Deep Brain Stimulation for Parkinson's
Deep brain stimulation uses a surgically implanted, battery-operated medical device called a neurostimulator. The neurostimulator is similar to a heart pacemaker and is approximately the size of a stopwatch. It delivers electrical stimulation to targeted areas in the brain that control movement, blocking the abnormal nerve signals that cause tremors and other symptoms of Parkinson's.
The deep brain stimulation system consists of three components:
- The lead
- The extension
- The neurostimulator.
The lead (also called an electrode) is a thin, insulated wire. The lead is inserted through a small opening in the skull and implanted in the brain. The tip of the electrode is positioned within the targeted brain area.
The extension is an insulated wire that is passed under the skin of the head, neck, and shoulder, connecting the lead to the neurostimulator. The neurostimulator (the "battery pack") is the third component, and is usually implanted under the skin near the collarbone. In some cases, it may be implanted lower in the chest or under the skin of the abdomen.
Once the system is in place, electrical impulses are sent from the neurostimulator up along the extension wire and the lead, and into the brain. These impulses interfere with and block the electrical signals that cause the symptoms of Parkinson's disease.
Unlike previous surgeries for Parkinson's disease, deep brain stimulation does not damage healthy brain tissue by destroying nerve cells. Instead, deep brain stimulation blocks electrical signals from targeted areas in the brain. Thus, if newer, more promising treatments develop in the future, the deep brain stimulation procedure can be reversed. Also, stimulation from the neurostimulator is easily adjustable, without further surgery, if the person's condition changes. Some people describe the stimulator adjustments as "programming."